Quercus cornelius-mulleri |
Quercus chapmanii |
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desert scrub oak, muller oak, muller's oak |
Chapman oak, Chapman's oak |
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Habit | Shrubs, evergreen or subevergreen, densely branched, 1-2(-3) m. Bark gray, scaly. | Shrubs, deciduous or subevergreen, 0.5-3(-6) m, often rhizomatous. |
Bark | brown, scaly. |
|
Twigs | gray, yellowish, or brownish, 1-1.5 mm diam., densely tomentulose, rarely glabrate. |
yellowish, 1-2 mm diam., densely fine-tomentulose. |
Buds | dull brown, ovoid, 2.5-3 mm, glabrous except for margins of scales. |
reddish brown, globose, 1-2(-3) mm, proximal scales densely tomentulose, distal scales glabrous. |
Leaves | blade strongly bicolored, ovate to oblong or narrowly obovate, 15-35 ×10-20 mm, rather thick and leathery, base cuneate or attenuate-rounded, margins entire or irregularly, shallowly toothed, teeth mucronate, rarely spinose, secondary veins 6-7 on each side, apex rounded or acute; surfaces abaxially whitish, densely covered with minute, compact, appressed, (8-)10-14(-16)-rayed stellate hairs less than 0.2 mm diam. (lateral fusion of rays visible under high magnification), without glandular seriate hairs, adaxially dull, light green, grayish, or yellowish green, with scattered, appressed-stellate hairs to 0.2 mm diam. |
blade obovate or oblanceolate, 30-70(-85) × 14-30(-45) mm, base cuneate or attenuate, margins minutely revolute, entire or sinuately lobed, sometimes obscurely 3-lobed distally or with 3-5 rounded, irregular lobes in distal 1/2, secondary veins curved, 8-9 on each side, apex ovate or triangular-lobed, often retuse; surfaces abaxially grayish or yellowish, with yellowish, erect branched hairs, these soon shed, leaving matted glandular and waxy hairs except on ± glabrate yellowish veins, adaxially bright glossy, very reflective, glabrous or with minute, scattered, stellate hairs. |
Acorns | solitary or clustered, subsessile; cup deeply cup-shaped or turbinate, to 5-13 mm deep × 12-20 mm wide, scales whitish or cream, strongly tuberculate especially near base of cup; nut dark brown, fusiform or cylyndric, 20-30 × 10-30 mm. |
1-2, on peduncle 1-6(-35) mm; cup hemispheric, 5-11 m deep × 10-15 mm wide, including 1/3-1/2 nut, scales closely appressed, gray, tomentulose; nut light brown, ovoid to barrel-shaped, 15-20 × 9-13 mm, apex rounded, glabrous or puberulent. |
Cotyledons | distinct. |
distinct. |
Quercus cornelius-mulleri |
Quercus chapmanii |
|
Phenology | Flowering early spring. | Flowering late winter–early spring. |
Habitat | Open chaparral, pinyon and juniper woodlands, desert margins, often on loose granitic soils | Open pine forests, scrublands, xerophytic scrub oak, on sand near coast |
Elevation | 1000-1800 m (3300-5900 ft) | 0-100 m (0-300 ft) |
Distribution |
CA; Mexico (Baja California)
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FL; GA; SC
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Discussion | Quercus cornelius-mulleri is easily distinguished from other California scrub oaks by the strongly bicolored leaves, dense minute tomentum of the abaxial leaf surface, and large acute acorns in deep tuberculate cups. Of greater difficulty are swarms of putative hybrids with Q. engelmannii, sometimes referred to as Q. ×acutidens. In Joshua Tree National Monument a lone tree and several shrubs appear to be hybrids and backcrosses between Quercus cornelius-mulleri and Q. lobata. This tree is the basis of Quercus ×munzii J. M. Tucker. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 3. | FNA vol. 3. |
Parent taxa | Fagaceae > Quercus > sect. Quercus | Fagaceae > Quercus > sect. Quercus |
Sibling taxa | ||
Name authority | Nixon & K. P. Steele: Madroño 28: 210. (1981) | Sargent: Gard. & Forest 8: 93. (1895) |
Web links |